These modules are supposed to be used with the Apache server together with
an embedded Perl interpreter like mod_perl. They provide support for basic
authentication and authorization as well as support for persistent database
connections via Perl's Database Independent Interface (DBI).

o AuthDBI.pm provides authentication and authorization:

  - optional shared cache for passwords to minimize database load
  - configurable cleanup-handler deletes outdated entries from the cache

o DBI.pm provides persistent database connections:

  - connections can be established during server-startup
  - configurable rollback to ensure data integrity
  - configurable verification of the connections to avoid time-outs.
